Centralized traffic controlling system for railroads



July 23; 1935. R. M. PHINNEY CENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed May 25, 1931 M23 zmPfim 20x23 mm 3 342m "6 ll Euufim mom M! mm 3 m 2 2w m mg TZQHm L O zotumqmm Wok 4%. ATTORNEY Patented July 23, 1935 CENTRALIZED TRAFFIC CONTROLLING Y SYSTEM FOR RAILROADS q Robert M. Phinney, Rochester, N.-Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application May 23, 1931, Serial No. 539,486

19 Claims.

This invention relatesto centralized trafiic controlling systems for railroads, and more particularly pertains to a system of the type employing direct linewire control for the switches and signals.

In accordancewith this invention, it is proposed to govern a railroad track switch over a polarized control circuit and to indicate over the same polarized circuit the locked condition of the associated track switch due to the approach locking and detector locking associated therewith. The invention provides that this control circuit shall be so governed bythe approach and detector locking that, if the operator moves the associated control lever to a new governing position while a trainis passing over the switch, the switch will not be operated either at that time or after the train has passed beyond the switch; but the operator is required to return the control lever into correspondence with the switch and then move it to a new position while the approach and detector locking is ineffective in order to obtain the desired Operation of the switch.

The present invention provides a second polarized circuit for the indication of the position and locked condition of the track switch both in the central control oifice and at the field station as well as its correspondence with the associated control lever. This polarized circuit is also employed in combination with the switch control circuit to indicate the passage of a train.

Theinvention provides a third polarized control circuit for governing the indications of the signals which set up routes for traffic over the track switch. These routes are selected in accordance with the correspondence between the control lever and the track switch as indicated over the second polarized circuit.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawing and in part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to the accompanying drawing which is a diagrammatic illustration of one specific embodiment of the present invention as applied to the control of traffic over a single railroad track switch.

Although the traflic controlling system of the present invention may be applied to various track layouts involving conflicting routes and non-conflicting routes and various other conditions encountered in interlocking practice, it has been specifically illustrated in the embodiment as applied to a single track switch and preferably associated with an automaticblock signal system of some suitable'type, such for example, as disclosed in the pending application of S. N, Wight, Ser. No. 120,423, filed July 3, 1926;

With reference to the accompanying drawing, a railroad track switch TS is illustrated as connecting the'rails 5 of a main track to the rails 6 of a diverging route or turn-out track. Thistrack switch TS is operated by a power driven switch machine SM which may be of any suitable type, I

such for example, asdisclosed in' the patent "to W. K. Howe Patent No. 1,466,903 dated September 4, 1923. r This switch machine is preferably pro vided with a dual control selector topermit hand operation of the track switch,'as shown for-ex ample, in the pending applicationof 'W. K. Howe, Ser. No. 354,039 filed April '10, 1929.

The main track adjacent the track switch TS and a portion of the diverging track upto the fouling point comprises a detector track section DS with the usual track battery and track relay T, which detector track section is insulated from the restof the track by-the usual insulated joints. Traffic over the track switchTS is preferably governed by signals l and IA for governing traffic in an east bound direction on the main track and onto the diverging track respectively; while signals 2 and 2A are preferably provided for gove erning traflic in a west bound direction on the main track and off the diverging track respectively. j

Associated with the signal I is a: home relay IH of the usual polar-neutral type, andsimilarly, associated with the signal IA is a home relay; I AH of the polar-neutral type. Theserelays l H and IAH are governed in accordance with traific conditions east of the signals 'I'I A on the main track and on the diverging track respectively. Likewise, associated with the signa1s 2- 2A- is-the home relay 2H of the usual polar-neutral type, which relay is governed in accordancewith traffic conditions west of the signals 2 -2A on' the main track. The control of these home relays has not beenillustratedas such control is well known to those skilled in the art, and is-shown', for example, inthe above mentioned, application 'of S. N. Wight, Ser. No. 120,423. M r

The track switch TS and the switch machine SM are preferably provided with point detector contacts (not shown) of some suitable type, as disclosed, for example, in the patent to C. S. Bushnell Patent No. 1,517,236 dated" November 25, 1924. These contacts are employed -to ener-- gize a switch repeating relay WP of r the usual polar-neutral type with one polarity when the track switch is in an extreme normal locked position, and to energize it with the opposite polarity when the track switch is in an extreme reverse locked position, or to deenergize this relay WP whenever the track switch TS is unlocked or the switch machine SM is in operation. Such control of the relay WP is well understood, and is merely indicated by a dotted line extending from the track switch TS and the switch machine SM.

A polar relay WZ of the magnetic stick type is governed from the control office over a suitable polarized line including line wire I and a common return line. The contacts of this relay, when operated to one or the other of their extreme positions, serve to operate the switch machine SM to corresponding normal or reverse extreme locked positions, which control is indicated by a dotted line.

A relay S2 of the polar-neutral type is governed from the control ofiice over a polarized circuit includinga line wire 8 and the common return line for the purpose of governing the operation of the signals ll A and 22A. This relay S2 is employed to select, in cooperation with a correspondence relay OR of the polar-neutral type, one of four signal control relays G, such as relays lG-IAG and 2G2AG. As obvious from the reference characters applied to the relays G, they are provided to control the respective signals llA and 22A which have been illustrated as being of the color'light type. These signals preferably display red or danger indications whenever the corresponding Grelays are deenergized and display green or yellow, proceed indications, whenever a corresponding G relay is energized and the traflic conditions, as indicated by the relays IH, IAH and 2H, are such that it is safe for trafllc to proceed. Although the control of the signals has been in part illustrated and in part indicated, it is to be understood that such control may include various other features so as to make the signals conventional stick signals, or illuminated only upon appreach, or the like, without departing from the present invention.

Associated with the relays IG and IAG is a neutral relay IM which is energized whenever these relays are deenergized; and similarly,.associated with the relays 2G and 2AG is a neutral relay 2M energized whenever these relays are deenergized; Thus, these relays lM and 2M are deenergized whenever their respective signals are giving proceed indications. A neutral relay M is governed by these relays IM and 2M and such other signals as maybe desired for a particular situation, so that the deenergization of the relay M indicates that certain signals associated with the track switch TS have been cleared for the passage of traffic thereover.

A time element device TE, a neutral stick relay S and a neutral lock relay L are associated with the track relay T and with the relay M in such a manner as to provide approach locking for the track switch TS with a suitable time release control, all of which has been more completely disclosed in my pending application Ser. No. 463,940 filed June 26, 1930. a

In the central control office, a suitable-control machine is preferably provided with the usual miniaturetrack diagram having control levers and indicators advantageously located thereon. For convenience in describing the present invention, only the-switch machine control lever SML and the. signal control lever SGL for governing the track switch TS .andits associated signals, have been shown. The switch machine lever SML is preferably of the two position quick acting type operating suitable contacts to either of two extreme normal or reverse positions; while the signal control lever SGL is of the three position type operating contacts to either of three corresponding positions.

The switch machine lever SML controls the relay WZ at the field station over a polarized circuit including the line wire 1, as previously mentioned, and including one or the other of two windings of a lock repeating relay LP depending upon the position'of the lever. The windings of this relay LP are connected differentially with respect to each other so that reversal of the lever SML and the reversal of polarity in the control circuit including the relays WZ and LP does not cause the deenergization of the relay LP for reasons more specifically pointed out hereinafter.

A polar-neutral relay WK is associated with the lever .SML and is controlled over a polarized circuit including indication line wire 9, the polarneutral correspondence relay CR and the common returnline. These relays WK and CR are so controlled by the relay WP and the control lever SML as to indicate the correspondence between the lever SML and the track switch TS as established during the control thereof.

A lock-out indicator in, a correspondence indicator H and; a track occupancy indicator l2 are controlled bythe relays LP and WK to give suitable information to the operator of the condition of the track switch TS.

'Both at the field station and in the control office, battery symbols have been employed in place of the actual connections to suitable batteries or other sources. Symbols and are employed to indicate connections to the positive and negative terminals of a suitable source local to either the control office or the field station where thus indicated. Circuits employing these symbols always have current flowing in'the same direction, when closed.

A battery l5 in the control office, and a battery H5 at the field station are provided for furnishing current for the line circuits. Each of these battery sources I5 and I6 has been pro vided with a center or intermediate tap connected to the common return line.

It is believed that further description of the present invention will best set forth the char: acteristicfeatures and functions of the system by considering the operation thereof under certain characteristic or typical conditions.

Operation Normal condit20ns.-With the track section DS unoccupied by a train; and with the control levers SML and SGL in the positions shown, the various devices, relays and circuits assume positions and conditions of energization, as illustrated. The track relay T is of course normally energized. With the signal lever SGL in a center or stop position, the relays IGIAG and 2G--2AG are deenergized which closes a circuit for the relay IM from through back contact 20 01 relay l G, wire 2|, back contact 22 of relay IAG, wire 23, winding of relay IM, to and similarly, for the relay 2M from through back contact 24 of relay 2G, wire 25, back contact 26 of relay ZAG, wire 21, winding of relay 2M, to This closes a circuit for the relay M from through. front contacts 28 and 29 of the relays IM and 2M respectively, windings of relay M, to

'flowingthrough this circuit the contacts of the 7 With the relays T and M energized, a stick circuit for the stick relay S is completed from through the heating element 30 of the thermal time element device TE, front contact 3I of stick relay S, wires 32, 33 and 34, windings of relay S, wires 35 and 36, front contact 3! of relay M, to It is noted, that the current, which flows through this circuit including the heating element 30, is of insufficient valueto effect the operation of the time element device TE, but is sufiicient to maintain the relay S energized.

Thus, an energizing circuit for the lock relay L is completed from through closed contact tact 52 of relay WK in a right hand position,

control line wire I to the field station, front contact 53 of lock relay L, windings of relay WZ, wires 54 and 55, to the common return line and thence to the mid'tap of the battery I5. This normal energizing circuit causes the contacts of the relay WZ to be actuated to right hand positions and the contacts of relay LP to be actuated to energized positions.

With the track switch TS in a normal locked position and the switch machine SM at rest, the neutral contacts of the relay WP are in energized positions and the polar contacts are in right hand positions. This causes the energization of the relays CR and WK, as the lever SML is in correspondence with the track switch TS, from the positive terminal of the battery I6, through wires 51 and 58, polar contact 59 of re- ,lay WP in a right hand position, front contact 60 of relay WP, windings of relay CR, front con tact SI of track relay T, indication line 9 to the control office, windings of relay WK, front contact 62 of lock repeating relay LP, wire 63, contact 65 of switch machine lever SML in a normal position, wires 66, 61, 68 and 69, to the negative terminal of battery I5, through the common return line to the mid tap of battery I6. With this normal indication circuit completed including a part of the battery I in the control oflice and a part of the battery I6 at the field station in series, the neutral contacts of the relays WK and CR are actuated to energized positions and the polar contacts are actuated to right hand positions.

Remote manual control of the track switch.- Let us assume that the operator moves the switch machine lever SML to a reverse dotted line position. The contacts of the lever SML are preferably of the quick acting type, so that the polarity is reversed upon the control circuit before the relay LP (which is slightly slow acting) can become deenergized and drop its contacts, thus completing the reverse control circuit including a stick contact of the relay LP from the negative terminal of the battery I5, through wires 69, 68, 61 and Ill, contact II of lever SML in a reverse position, upper winding of lock repeating relay LP, wires I2 and I3, front contact I4 of relay LP, wires I5 and 5I, polar contact 52 of relay WK in a right hand position, control line wire I, front contact 53 of relay L, winding of relay WZ, wires 54 and 55, through the common return line to the mid tap of battery I5. With current .ence indicator I I.

relay 'WZ are actuated to reverse left hand positions governing the switch machine SM in a manner to unlock the track switch TS and operate it to a reverse locked position.

The initial reversalof the switch machine lever SML connects the positive terminal of battery I5 to the indication circuit including relays WK and CR, thus placing the lefthand portion of battery I5 in multiple with the right hand portion of battery I6 which deenergizes the relays WK and CR. During the operation of the track switch TS and switch machine .SM, the relay WP is deenergized which further insures the deenergization of the relays WK and CR. This indicates both at the field station and at the control oflice that the lever SML is out of correspondence with the track switch TS, which is made known to the operator by the illumination of the correspond- The indicator II is energized from through back contact I6 of relay WK, front contact 11 ,of relay LP, indicator I I,

'The reverse control circuit includes the stick contact I4 of the lock repeating relay LP until the track switch TS is operated to a reverse locked condition, as the polar'contacts of the relay WK remain in their last actuated positions until the relay is energized with the opposite polarity.

Upon the completion of the operation of the track switch TS to a reverse locked position, the relayWP is energized with the opposite polarity actuating its polar contacts to reverse positions and its neutral contacts to energized positions. Thus, the track switch TS and switch machine lever SML are in corresponding reverse positions so that an energizing circuit for the relays WK and OR is then completed from the negative terminal .of battery I 6, through wires I8 and I9, polar contact 59zof reIay'WP in aleft hand position, front contact 60 of relay WP, windings of relay CR, front contact SI of relay T, indication line 9, windings of relay WK, front contact 62 of relay LP, wire'"63, contact 65 of lever SML in a reverse dotted line position, wires 80, 46, 45 and 44, to thepositive terminalof battery I5, through the common return line to'the mid tap of battery IS. The polar contacts of the WK and CR relays are actuatedto reverse or left hand dotted line positions and their neutral contacts are actuated to energized positions. The operation of polar contact 52 of relay WK is sufliciently quick to complete an energizing circuit through the upper winding of relay LP from wire I2, through wire 8I, polar contact 52 of relay WK in a left hand position, to line wire I, so that relay LP is maintained energized.

The energization of relay WK also opens the,

energizing circuit of indicator II at back contact 16, informing theoperator of the correspondence of the track switch with the control lever.

Thus, an operation of the track switch TS from its normal locked position to its reverse locked position has been described in detail. The operation involved in operating the track switch from the reverse locked position to a normal locked position is merely the inverse of that operation already described and will not be specifically pointed out, as such operation may be understood by analogy, considering that the lever SML returned to the normal position reverses the polarity energized through its stick contact 14 in a simila manner as already described.

, Remote manual control of the signals.--Assuming proper trafiic conditions, either the signal I or the signal 2 may be cleared with the track switch TSin a normalposition; while either the signal IA or the signal 2A.may be cleared with the track switch TS in a reverse position. These signals i-iA and 2-2A are governed in accordance with whether the signal leverlSGL is moved to the right or to the left, which allows the operator to establish trafiic in either east or west bound directions.

Let us assume that the track switch TS is in a normal position with the lever SML in correspondence therewith, and that the operator desires to clear the signal I to establish trafiic in an east bound direction over the main track. To

.do this, he moves the signal lever SGL to a right hand position completing the signal control circuit from the negative terminal of the battery I 5, through wires 59 and 82, contact 83 of signal lever SGL in a right hand dotted line position, line wire 8, windings of relay SZ, wires 84 and 55, through the common return line to the mid tap of battery l5.

' The current flowing in this signal control circuit actuates the polar contacts of the relay SZ to left hand positions and its neutral contacts to energized positions. An energizing circuit for the relay i G is thus completed from through front contact 85 of track relay T, wire 86, front contact 87 of relay SZ, wire 88, polar contact 89 of relay SZ in a left hand position, wire 90, front contact ill of relay 2M, wire 92, front contact 93 of relay CR, wire 94, polar contact 95 of relay CR in a' right hand position, wire 96, front contact 91 of relay 1H, wire 98, winding of relay IG, to

It is noted, that traffic in advance is assumed to be such that there are no trains in the next track section in advance of the signal I so that the relay EH is energized. If there is a train in the second section in advance, the relay IH is energized with one polarity; While, if a train is in the third section in advance, the relay IE is energized with the opposite polarity. Thus, the energization of the relay lG causes the signal I to give yellow or green proceed indications in accordance with traflic conditions in advance as indicated by the relay EH. These conditions have been chosen for convenience in describing the invention, but may vary in accordance with the conditions of practice which must be met in a particular situation.

The energization of the relay lG opens the energizing circuit of the relay IM at back contact 20, which deenergizes the relay I M and prevents the clearing of the opposing signals 2- 2A.and also the operation of the switch machine SM in a manner presently to be described. The deenergization of relay M my open front contact 28, deenergizes the stick relay S at front contact 3i which in turn deenergizes the lock relay L at front contact 40 opening the control of the relay WZ at front contact 53. This prevents the operator from reversing the polarity upon the relay WZ during any time that a signal governing traflic over the track switch TS is clear.

During the deenergization of the relay L, energy is applied to the windings of the relay WZ through what may be termed a holding or stick circuit, the polarity of which corresponds to the last polarity applied to the relay. This holds the contacts of the relay WZ in their last operated positions during the time that its control circuit is opened by the relay L. In this case,

for example, the relay NZ is energized from the positive terminal of the battery 56, through wires 5! and [D1, polar contact 162 of relay WZ in a right hand position, wire 803, back contact ,53 of relay L, windings of relay W'Z, wires 54 and -55, to the mid tap of battery I S.

During the time that the signal 'I is cleared and the lock relay'Lis deenergized, the switch control circuit including the relay LP is opened at front contact 53, as previously pointed out. This deenergizes the relay LP causing the look-out indicator lamp in to be energized through a circuit obvious from the drawing and including back contact Hi l, which informs the operator that the track switch TS is properly'locked. The deenergization of relay LP also opens front contact 62 and closes a holding circuit for the relays WK and CR. For example, assuming the track switch TS and lever SML to be in corresponding normal positions at the time of deenergization of the relay LP, then a holding circuit is closed from the positive terminal of battery [6, through wires, 5i and 58, polar contact 59 of relay WP inxa right hand position, front contact 60 of relay WP, windings of relay CR, front contact 65 of. relay '1, line wire 9, windings of relay WK, back contact 32 of relay LP, wire H5, front contact iifi of relay WK, wire H7, polar contact H9 of relay WK in a right hand position, wires Hill, E38 and 69 to the negative terminal of battery l5 through the common return line to the mid tap of battery it.

Thus, with the lock repeating relay LP deenergized, movement of the lever SML will neither effect the operationv of the switch machine SM nor the condition of the signals which are selected through the relays WK and CR.

The operator mayl return the signal I to indicate red or stop, at anytime he may desire, by returning the signal lever to its central position, which deenergise-s the relay SZ and opens the energizing circuit for the relay [G at front contact 81.

Approach, locking and time releasa-If the operator anticipates the. approach of a train and sets up a particular route by clearing a signal for that route, as above explained, and then changes his minclfor one reason or another and endeavors to alter the route already established, he is prevented from operating the track switch for a predetermined time after the signals governing that route have been returned to stop conditions. This predetermined time is measured by the time element device TE, which includes both the heating and cooling time of its thermal elements, as more specifically pointed out in my above mentioned pending application Ser. No. 463,940.

For example, assuming the operator returns the signal irto stop, then the resulting energization of the relay M closes a circuit from through the heating element 38 of the thermal time element device TE, back contact 3! of relay S, wires IE5 and front contact 3'! of relay M, to It is noted, that the current which flows in this circuit is suilicient to cause the heating element 36 to actuate the contacts 906 to closed positions and open contacts 38. The closure of contacts 5% completes a'pick-up circuit for the relay S from through closed contacts I05, wires l6! and 34, windings of relay S, wires 35 and 36, front contact 3"! of relay M, to The energization of the relay S is maintained through its stick circuit as previously traced, and the energizing circuit for the heating .element 30 is opened atback contaot'3l thus'allowingthe thermal .time element device TE'to .cool sufliciently to again close back-contacts 38 and open,

contacts I06. Closed contacts 38 complete the circuit for the relay L, as previously pointed out. With the relay L energized, the relay LP is energizedif the lever SML is still in correspondence with the track switch TS.

. Thus, the operator may changea route only after a predetermined time in the face'of an oncoming train, which allows the train sufiicient time toeither stop before it reaches'the track switch TS or to enter the detector track section and thereby prevent. the operation of the switch machine. 1

, On the other hand, if the operator clears signal I as. above described for establishingan east bound. route over the main track, a train may proceed to accept the signal I and pass onto the detector track section DS. This shunts or deenergizes the track relay T which further opens the energizing circuit of the, relay L at front contact 43. The entrance of a train onto the detector track section after the acceptance of signal I, opens the energizing circuit for the relay IG at front contact85: causing the signal I to indicate stop or red. As soon as the relay lG is deenergized, the energizing circuit for the relay IM is completed at back contact 20 which in turn closes the. energizing circuit for the relay M at front contact 28. This closes thefront contact 31 of relay M and asthe track relay T is deenergized, a pick-up circuit for the relay S is completed from (-1 through back contact Hi3 of 1 relay T, wires I l I, 33 and34, windings of-relay S,

Wires 35 and 36, front contact 3'! of relay to This energizes the stick relay S immediately without the intervention of a predetermined time period as provided by the time element device TE.- This does not release the locking, as the track relay'T is deenergizedso long as the train is on the track section DS, thereby maintaining the circuit for relay L opened at front contact 43. V

In other words, approach locking is provided which locks the switch machine from manual manipulation upon the establishment of a routev until after the passage of a train, but which may be released without the passage of a train only after a predetermined time has elapsed subsequent'to the returning of that route to stop.

The operator is informed of the passage of the train by the illumination of track occupancy indicator l2. This is accomplished upon the deenergization' of the track 'relayT with' the lock relay LP deenergized, by opening the energizing circuit for the relay WK at front contact 6!. The energizing circuit for the track occupancy indicator I2 is closed from through back contacts 16 and I! of relays WL and LP respectively, indicator lamp l2, to

' Upon the passage of the train onto the detector track section DS, the operator may place the signal lever SGL in the central or stop position to prevent the passage of subsequent or following trains, or automatic means maybe provided to make any one or all of the signals what iscommonly termed, stick'signals. In any event a signal, as for example signal I, remains at stop after the passage of the train, until the train has passed out of the territory governed by that signal, all in accordance with the automatic signalling associatedtherewith, in which case the stick relay S remains energized and the lock relay L is energized so soon astrack relay T'is energized. Withsthe lock relay L again energized (with the signal'lever SGL in a stop or central position), the operator may then control the track switch in the usual Way, thelock repeating relay LP immediately. being energized as the lever SML is left in correspondence with the track switch TS until the lock-out indicator Ill is not illuminated.

Correspondence between control lever and track switch required.The deenergization of-the lock relay L opens the control circuit including the windings of the lock repeating relay LP, as above pointed out; or in other words, the relay LP repeats without exception the deenergiz'ation of the lock relay L. However, upon the reenergization of the lock relay L, the relay LP is only energized or picked up providing the lever SML is in correspondence with the track switch TS.

This feature provides that, if the operator preconditions a route including the track switch TS during the passage of a-train thereover or at any other time that the lock relays L and LP are deenergized and the look-out indicator l0 illuminated, such preconditioning is ineffective to control thetrack switch TS upon the reenergization of the lock relay L. This requires that the operator returnhis lever SML to a position in correspondence with the track switch TS before he can again obtain control thereof, which results in the individual consideration of each routeat the time that it is established and allows such route to be established only at a proper time;

The means employed for accomplishing this.

feature is provided by the stick contact M of relay LP and the circuits which have been already pointed out as involving this stick zcontact; More specifically, with the lever SML and track switch TS in corresponding normal positions, the ener-' gizing circuit for the relay LP includes its lower winding and contacts 48 and 52 in corresponding normal positions; and similarly, with the lever SML and track switch TS incorresponding re-; verse positions, the energizing circuit for the relay LP includes its, upper winding and contacts H v and 52 in corresponding reverse positions. It is obvious, that if either of these circuits are opened and then closed by the look relay L, that the relay LP will repeat such conditions.

However, with the contacts 33 than out of corresponding positions, the normal and reverse energizing circuits then completed include the front contact M of the relay LP, as above pointed out. Thus, when such circuits are opened'by the relay L being deenergized, they cannot be closed upon the reenergi'z'ation of relay L by reason of open front contact 14. This requires that, after the relay L has been-'reenergized, the

lever SML must be moved so that contacts 48 and 52 are in correspondence to pick up the relay LP, and then moved to the new governing position to obtain the desired response of the" switch machine SM.

This organization of the system which prevents the response of the switch machine SM to the lever SML, if the lever is operated while the lock relays -L and LP are deenergized, also serves the purpose of preventing the undesired operation of the track switch TS while a train is passing thereover should a momentary loss of shunt occur allowing the momentary picking up of the track relay T. For example, if the operator should move the lever SML to a new position while a train is passing over the track switch TS, the look relay L would bedeenergized although the relay M would be picked up as the signals gov-' erning the passage of the train are at-stop due to the presence of the train. Thus, if the track relay T of the detector. track section DS should for one reason or another happen to momentarily pick up, the relay L would immediately respond closing the circuit from the lever SML to the relay WZ were it not for the lock repeating stick relay LP, which cannot be energized until the lever SML is returned into correspondence with the track switch. In brief then, the relay WZ cannot be controlled by the lever SML although a momentary lossof shunt occurs while a train is passing over the detector track section DS;

, Selection of signals for conflicting routes.-- The system of the present invention has been shown applied to a single track switch having four routes thereover, but it is to be understood that this track switch may be included in various track layouts, including other routes which conflict with those which may be established over the track switch TS illustrated. In such a case,

it is necessary to interlock or so interrelate the control circuits for the signals governing these other routes that they may be cleared only when the track switch TS is in proper position in correspondence with the control as established by the lever SML. The present invention provides that thesignals associated with these conflicting routes may be interlocked or selected either at the control office or at the field station or both by carrying their circuits through contacts on the relays WK and CR, as indicated in the drawing by the legends.

To summarize, a system for the control of a railroad track switch and its associated signals has been disclosed wherein the establishment of a route over that switch prevents the operation of the switch until that route has been returned to stop, irrespective of the movement of the switch control lever. The system further provides that the erroneous movement of the switch lever while the switch is locked, will not alter the route then established, nor will the track switch respond to an erroneous switch lever movement during the passage of a train should a momentary loss of shunt occur in the detector section over which the train is passing.

The locking of the switch normally requires the passage of a train to release it, but to prevent a tie up of traffic in the event that it is necessary to alter a route once established, a time release device is provided therewith.

The control of each track switch, irrespective of the track layout, is accomplished over three polarized circuits in the specific embodiment, but it is to be understood that the same principles involved may be applied to systems where all the interrelation of switch and signals is located in a central tower.

Having described a centralized traific control system, as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

Having described my invention, I now claim:--

1-. In a centralized trailic controlling system for railroads, a track switch, a control lever, a switch control relay for operating said trackswitch when actuated by said control lever, signals for setting up routes over said track switch, locking: means preventing actuation of said switclr con-' trol relay whenever a route is set up over said track switch and for a predetermined time after the signal for that route is put to stop irrespective of the presence ofa train approaching said switch, and means requiring. said control leverto be in' correspondence with said track switch subsequent to the unlocking of. said locking means before said: operating means can be actuated by said control. lever.

2; In a centralized traiiic' controlling system for railroads, a track switch, a control lever, operating means for operating. said track switch when actuated by said control lever, signals 101i setting up routes over said: track switch, and locking means preventingv actuation of said op-' erating means whenever a' route is' set up" over.- said track switch and for a predetermined: time after that route is put to stop,.said locking means including a stick relay having a pick-up circuit closed only when said cont'rol' lever and: said track switch are in correspondence and: all routes over that switch are at stop, a stick circuit for said stick relay, and: means opening said stick. circuit for said stick relay when said lever is out of correspondence'with' said track switch andsai'd locking means prevents actuation of said operating means, whereby said control lever isrequired. to be in correspondence with said track switch. subsequent to the effective condition of said lock-- ing means before said operating means can be actuated by said control lever 3. In a centralized trafiic controlling system for railroads, a track switch, a; switch machine for operating. said track switch-a polarized switchcontrol relay, a controli lever operable to either of two positions, a switch repeating relay governed inaccordance with theposition and locked condition of said track switch, a lock repeating: relay having two windings diiferentiallyconnect ed, a normal control circuit for said switch c'on-- trol relay having current flowing in one direction, said circuit including. said control lever in one position in correspondence with said switch re-' peatin'g relay and one of thewindings of said lock repeating relay, a reverse control circuit for said switch control relay having current flowing in the opposite direction, saidcircuit including said. control lever in the other position in correspondence with said switch repeating relay in the other position and the other winding of said lock repeating relay, a stick circuit including a front contact of said lock repeating relay for shunting the contact of said switch repeating relay, and a lock relay for opening and closing said normal and reverse control circuits; in accordance with the conditions of trafiic over said track switch.

4. In a centralized traiiic controlling system for railroads, a track switch, aswitch machine for operating said track switch, a control lever for governing, said switch machine; a polarizedindication circuit having a'current-fiowing, in one direction with said trackswitchin one position with said control lever in correspondence therewith andhaving current flowing inthe opposite direction with the track switch in an opposite position with said control lever in correspond ence therewith but having no current flowing therein when said control lever and said track switch are out of correspondence, a polar neutral relay included in said indication circuit at said control lever, another polar neutralrelay included or the negative terminal of saidway station split a in said indication circuit at said switch, a lock repeating relay at said lever governed in accordance with traffic conditions at said switch, means disconnecting said indication circuit from said lever and closing a stick circuit includingcontacts of said one polar neutral relay when said lock repeating relay is deenergized; and signals governing traffic over said switch,'said signals being selected in" accordance with said another polar neutral relay, whereby the operation of said control lever during the time said lock repeating relay is deenergized is ineffective with respect to said signals.

5. In combination, a track switch, a switch masaid control lever subsequent to the releasing o1 said approach locking means if said control lever is out of correspondence with'said track switch;

6. In combination, a controlled device, a lever having snap-acting contacts, a neutral relay being relatively slow acting with respect to said snap-acting contacts, control circuits for said controlled device being in part pick-up circuits for said neutral relay when said snap-acting contacts are in correspondence with said controlled device and being in part sti'ck ci'rcuits for said neutral relay when said snap-acting contacts are out of correspondence with said controlled device, and locking means at-times-opening said control circuits, whereby said neutral relay is attimes deenergized by said locking'means thereby preventing control of said controlled device by said snap-acting contacts subsequent to the closure of said controlcircuits' by said locking means'if said snap-acting contacts are out of correspondence with said controlled device;

'7. In combination, a controlled device', a lever having snap-acting contacts, a neutral relay being relatively slow-acting with respect to said snap-acting contacts, a front contact onsaid neutral relay, control circuits for said controlled dc vice, said circuits including said snap-acting'contacts and windings on said neutral relay at all times and including said front contact when'said snap-acting contact is out of correspondence with said controlled device, and locking meansat times opening said control circuits, whereby said neutral relay, when deenergized, prevents control of said controlled device, and whereby said neutral relay remains deenergized subsequent to theclosing of said control circuits'by said'locking means if said snap-acting contact is out'of correspondence with said controlled device. I 8. In combination, a central oflice and a distant way station, a track switch at said way station, a switch machine for operating said track switch, a control lever in said oilice for controlling said switch machine, a polar indication relay in said office, a split battery at said office and at said way station said batteries having their midpoints connected togetherya contact controlled by, said switch machine for connecting either the positive battery to one terminal of saidp'olar indication relay, and a contact on said lever for connecting 9. In combination, a central office and a distant way station, a track switch at said way station, a switch machine for operating said track switch, a control lever in said ofiice for controlling said switch machine, a polar indication relay in said ofilce, a split'battery at said OffiCG- and at said way station said batteries having their midpoints connected together, a contact controlled by said switch machine for connecting the positive and the negative terminal of said way station split battery to one terminal of said polar indication relay when said switch machine assumes respectively the normal and the reverse position, and a contact on said lever for connecting the negative andthe positive terminal of said ofiice split battery to the other terminal of said polar indication relay whensaid lever assumes respectively the normal or the reverse position, whereby said polar indication relay is energized only if said lever and said switch machine are in correspondence.

10. In combination, a central offi ce and a distant way station, a track switch at said way sta-, tion, a switch machine for operating said track switch, a control lever in said office for controlling said switch machine, a polar indication relay in said ofiice, a split battery at said ofiice and at.

whereby said polar indication relay is energized to its normal position only when both said lever and switch machine assume the normal position and is energized to the reverse position only if both said lever and said switch machine assume the reverse position. e

' -,11. In combination, a railway switch havin normal and reverse positions, a manually operable switch lever having normal and reverse positions for governing said railway switch, a signal governing traific over said switch, means for causing said signal to at times indicate proceed, a three-position polar indication relay, means for supplying said polarized indication relay with current of one polaritywhen said switch and. said switch lever both occupy their normal positions, means for supplying said polarized indication relay with current of the opposite polarity when said switch and said switch lever both occupy their reverse positions, means energizing said polarized indication relay with said one polarity or said opposite polarity in accordance with the normal or reverse position respectively of said track switch independently of said switch lever when said signal is caused to indicate proceed,

and traffic governing means controlled by said- Polarized indication relay.

12. In combination, a railway switch having normal and reverse positions, a manually operable switch lever having normal and reverse positions, a signal governing trafiic over said switch, means for causing said signal. to at times indicate proceed, a three-position polar indication relay, means for initially supplying said polarized indication relay with current of one polarity when and only when said switch and said switch-lever both occupy their normal positions, means for initially supplying said polarized indication relay with current of the opposite polarity when and.

13. In a centralized traflic controlling system:

for railroads; a track switch; a switch machine for operating said track switch; a control lever for governing the operation of said switch ma-' chine, when rendered effective; a lock relay for rendering said control lever effective when said lock relay is energized; a signal for governing trafilc over said track switch; means for energizing said lock relay only when said signal indicates stop; indication means for indicating the correspondence between said track switch and said control lever; means for manually govern-- ing said signal when said indication means indicates correspondence between said lever and said track switch; and means'both for rendering said control lever ineffective to govern said switch machine subsequent to the deenergization of said lock relay until said control lever has been in correspondence with said track switch following the energization of said lock relay, and for rendering said indication means independent of said control lever until said control lever has been in correspondence with said track switch subsequent to the deenergization of said lock relay and following its energization.

14. In a centralized traflic controlling system 'for railroads, one trafiic controlling device, a lever having snap acting contacts, a neutral relay being relatively slow acting with respect to said snap acting contacts, a front contact on said neutral relay, control circuits for said one controlled device, said circuits including said snap acting contacts and windings on said neutral relay at all times and including said front contact when said snap acting contacts are out of correspondence with said one controlled device, locking means at times opening said control circuits whereby said neutral relay is deenergized and whereby said neutral relay remains deen'ergized subsequent to the closing of said control circuits by said locking means if said snap acting contacts are out of correspondence with said one controlled device, another controlled device, means governing said another controlled device depending upon correspondence between said one controlled device and said control leverwhen said neutral relay is energized and independent of such correspondence when said neutral relay is deenergized.

15. In combination, a control location; a distant traific controlling device, a single line circuit connecting the control location. and the aware? distant trafllc controlling device, a control lever at the control location effective to energize said line circuit: with opposite polarities of current,

a polarized relay at the distant traffic controlling device said polarized relay being-included in said polarized line circuit and caused to assume opposite positions depending upon the polarity of current applied to said line circuit by said control lever, indication transmitting means necting the control location and the distant traific controlling device, a control lever at the control location efifective to energize said line circuit with opposite polarities of current, a polarized relay atthe distant trafiic controlling device said polarized relay being included in said polarized line circuit and caused to assume opposite positions depending upon the polarity of current applied to saidline circuit by said control lever, indication transmitting means for at times opening said line circuit in accordance with the condition of said traffic controlling device, a double winding indication relay differentially connected in. said line circuit depending upon the position of said control lever, whereby a reversal of the polarity in said line circuit by said lever maintains the'same direction of magnet flux in said indication relay to thereby render said indication relay unafiected by a change in the positions of said control lever, and indication means controlled by said indication relay.

17-. In combination, a line circuit connecting a control location and a distant trafiic controlling device, a source of energy at the control location, a control lever for applying opposite polarities of current to said line circuit from said source of energy, a polar relay included in said line circuit and responsive to the polarity of current in said line circuit to control the trafiic controlling device, indication transmitting means for at times opening said line circuit and controlled in accordance with the condition of said traflic controlling device, a double winding difierential relay having one winding or the other connected in series in said line circuit in accordance' with the position of said control lever so as to be responsive to the opening of said line circuit by said indication transmitting means but to be unafiected by the operation of said lever to reverse. the polarity of the current in said line circuit, and indication means controlled by said double winding differential relay.

18. In combination; a track switch; a switch machine for operating said track switch; signals for governing traffic. over said track switch; a switch machine control lever; a switch machine control relay for controlling the operation of said switch machine; a circuit for said switch machine control relay governed by said control lever; approach locking means conditioned to prevent the governing of said switch machine control relay by' said control lever when said signals. are conditioned to allow the passage of traflic over said track switch; means restoring said approach locking means to allow the governing of said switch machine control relay by said switch machine control lever, said restoring means being effective a predetermined time after said signals have been conditioned to prevent movement of trafiic over said track switch and said restoring means acting irrespective of a train approaching said switch; and means preventing the control of said switch machine control relay by said control lever subsequent to-the restoring of said approach locking means only if said control lever is out of correspondence with said track switch upon such restoration.

19; In combination; a track switch, a switch machine for operating said track switch; signals for governing trafiic over said track switch; a switch machine control lever; a switch machine control relay for controlling the operation of said switch machine; a circuit for said switch machine control relay governed by said control lever; approach locking means conditioned to locking means a predetermined time after said signals have been conditioned to prevent movement of traflic over said track switch; if not restored by the detector track relay, said automatic 'means acting regardless of the presence of a train approaching the switch; 'and means preventingthe control of said switch machine control relay by said control lever subsequent to the restoring of said approach locking means only if said control lever is out of correspondence with said track switch upon such restoration. 2

ROBERT M. PHINNEY. 

